Unitary disposable absorbent articles such as catamenial pads or incontinent pads all have the same basic structure. An absorbent core is encased between a liquid pervious topsheet and a liquid impervious backsheet. Numerous variations of and elements in addition to the basic topsheet, backsheet, and absorbent core arrangements are known. Each additional element is usually directed to improving a specific characteristic of the catamenial pad or incontinent pad.
Disposable absorbent articles have been provided with elastic members to improve the side leakage performance of such products. U.S. Pat. No. 3,860,003, issued to Buell on Jan. 14, 1975, discloses elasticized disposable absorbent articles wherein an elastic member is positioned in the side flap of the product between the topsheet and the backsheet. The elasticized portion of each side flap is positioned sufficiently remote from the semi-rigid absorbent body to permit an elasticized contractible line through the side flap. The side flap is gathered by the elastic member such that a boat-like configuration for the pad is presented and the side flaps form a barrier along the edges of the product. In particular, FIG. 5 and FIG. 6 show incontinent pads having various shaped absorbent cores wherein an elastic member is positioned along the side edges of the product.
European Patent Application 0 091 412 A2, Widlund, published on Oct. 12, 1983, adopts the configuration shown in the Buell '003 patent and specifically relates it to a feminine hygiene product. The Widlund application teaches a sanitary napkin with elastic means spaced from the core to thereby raise and form barriers against lateral leakage from the product. FIG. 1 of the Widlund patent shows the boat-like shape of the product with the side flaps forming lateral barriers to the flow of exudates.
U.S. Pat. No. 4,597,761 issued to Buell on Jul. 1, 1986, discloses an elasticized insert product for use as an incontinent pad or sanitary napkin having elastic in the side flaps. One or more elastic strands are positioned in the side flap to allow the product to assume the boat-like configuration shown in FIG. 1 with the side flaps extending upwardly to form barrier walls against lateral leakage.
U.S. Pat. No. 4,579,556 issued to McFarland on Apr. 1, 1986, further defines the Buell '003 concept for incontinent pads by creating a dual baffle structure at the edges. The impervious backing sheet is folded over the topsheet and the absorbent layer and fastened to the topsheet so that when the elastic contracts, the pad bows with the elasticized fold raising above the surface of the pad to form a baffle. A lower baffle is formed over the absorbent with the upstanding baffle containing the elastic.
U.S. Pat. No. 4,668,230 issued to D'Amico et al. on May 26, 1987, adopts the Buell '003 approach and the Widlund application approach by extending the elastics to the ends of the pad and allowing the pad to assume a cup-like or boat-like shape. In particular, the elastics are secured at one end of the pad and extend at least two-thirds of the length of the remainder of the pad to give the proper trough-like shape to the pad. However, side flaps that stand up are not created in the D'Amico et al. patent.
UK Patent Application 2 168 253A, Baird and Robertson, published on Jun. 18, 1986, discloses an incontinent pad or sanitary napkin provided with liquid impermeable upwardly folded side flaps. The side flaps are formed by extending the backsheet beyond the absorbent core along at least part of the lateral edges of the absorbent core. A seal is formed adjacent the side edge of the absorbent core to present a dual baffle against leakage in the sides of the pad.
U.S. Pat. No. 4,701,177 issued to Ellis et al. on Oct. 20, 1987, provides a pad that is generally thicker in the center portion than at the ends of the pad. The upstanding side portions in the middle of each longitudinal edge are in the area where the absorbent core is hourglass or narrower shaped. The pad is also curved into a boat-like shape to generally conform to the pudendum of the wearer. The elastic film members are secured in the side flap of the sanitary napkin or incontinent pad between the topsheet and the backsheet to form the upstanding baffles.
U.S. Pat. No. 5,032,121 issued to Mokry on Jul. 16, 1991 adopts the Buell '003 and Widlund approach by placing the elasticized baffles in an hourglass-shaped pad with an hourglass-shaped absorbent core. The sanitary napkin includes a pair of elastic members affixed between the cover and the backsheet outward of the seal line and aligned adjacent to the central portion of the core. The elastic members cause the pad to acquire a cup-shaped configuration which corresponds to the perineal area of the user.
Each of these patents are related to providing elasticization in a sanitary napkin or incontinent pad. In each of these concepts, the elastic members are positioned in the side flap between the topsheet and the backsheet to allow the side flap to be gathered and to form upstanding baffles along the side edges of the product to slow or stop the lateral flow of body exudates beyond the edge of the pad. However, each of these approaches suffer from the fact that the backsheet and topsheet edges of the product are allowed to contact the wearer during use. The tension created by the elastic members in contracting these portions of the topsheet and the backsheet create a relatively rough surface adjacent the skin which can rub or chafe the wearer. Further, it has been found that relatively high tensions within the side flaps of the absorbent core may further reduce wearer comfort as well as the inherent bunching of the product by the wearer squeezing the thighs together.
In catamenial pads it is particularly desirable to improve wearing comfort while preventing increased soiling of the garments surrounding the pad. It is also desirable to provide catamenial pads having soft lateral edges to increase the wearer's comfort.
Therefore, it is an object of the present invention to provide a disposable absorbent article providing improved protection against soiling while providing improved wearer comfort.
It is a further object of the present invention to provide an elasticized catamenial pad or incontinent pad that protects against lateral soiling while improving the wearer's comfort.